Method of printing smooth micro-scale features

Abstract

A method of jet-printing smooth micro-scale features is presented. The desired feature prior to being printed is masked by various decimation filters and the decimation is performed at various pitches. The subsequently printed image is then scanned and analyzed to determine the roughness of the lines. The optimum decimation pitch is determined by the feature that exhibits the least amount of droplet spreading and has the lowest edge roughness. The optimum decimation pitch may also be calculated from the material properties and the dynamics of fluids.

1. A method of forming smooth micro-scale features with printed spots on a substrate using a printing system having a printing process direction and one or more print heads with one or more ejectors on each print head, the method comprising:
 determining the radius of the printed spots; 
 creating a test pattern; 
 printing the test pattern with the printing system; and 
 analyzing the printed test pattern for drop spreading and smoothness of lines. 
 
   
   
     2. The method defined in  claim 1 , wherein the test pattern comprises successive patterns of spot features of varying spot placements demonstrating variations in spot placement pitch and adjacent drop timing. 
   
   
     3. The method defined in  claim 2 , wherein the test pattern is printed in the process direction. 
   
   
     4. The method defined in  claim 2 , wherein the test pattern is printed in the non-process direction. 
   
   
     5. The method defined in  claim 1 , wherein the printing system has multiple print heads with ejectors. 
   
   
     6. The method defined in  claim 5 , wherein the test pattern is printed by ejectors from different print heads. 
   
   
     7. The method defined in  claim 1 , wherein analyzing the printed test pattern further comprises for a known position of the test pattern:
 (a) calculating a figure of merit which describes the linewidths; 
 (b) calculating a figure of merit which describes the roughness; 
 (c) determining whether the optimal linewidth and roughness is achieved; and 
 (d) post baking the substrate if the roughness is not acceptable. 
 
   
   
     8. The method defined in  claim 7 , wherein the linewidth figure of merit is the average, minimum and maximum of a line region. 
   
   
     9. The method defined in  claim 7 , wherein the roughness figure of merit is equal to the maximum linewidth minus the minimum linewidth of a line region. 
   
   
     10. The method defined in  claim 1 , wherein image components to be printed are oriented relative to the printing process direction to produce smooth micro-scale features. 
   
   
     11. A storage medium storing a set of program instructions executable on a data processing device and usable to form smooth micro-scale features with printed spots on a substrate using a printing system having a printing process direction and one or more print heads with one or more ejectors on each print head, the set of program instructions comprising:
 instructions for determining spot placement pitch and the radius of the printed spots; 
 instructions for creating a test pattern; 
 instructions for printing the test pattern with the printing system; and 
 instructions for analyzing the printed test pattern for drop spreading and smoothness of lines. 
 
   
   
     12. The storage medium defined in  claim 11 , wherein the test pattern comprises successive patterns of spot features of varying spot placements demonstrating variations in spot placement pitch and adjacent drop timing. 
   
   
     13. The storage medium defined in  claim 11 , wherein the set of program instructions further comprises algorithms for the determination of test patterns for the determination of optimal spot placement to produce smooth line edge features and narrow linewidths. 
   
   
     14. The storage medium defined in  claim 11 , wherein the set of program instructions further comprises algorithms for the analysis of test patterns for the determination of optimal spot placement to produce smooth line edge features and narrow linewidths. 
   
   
     15. The storage medium defined in  claim 11 , wherein the printing system has multiple print heads. 
   
   
     16. The storage medium defined in  claim 11 , wherein the set of program instructions for analyzing the printed test pattern further comprises:
 (a) instructions for calculating the average, minimum and maximum linewidths; 
 (b) instructions for calculating the roughness, where the roughness is equal to the maximum linewidth minus the minimum linewidth; 
 (c) instructions for determining whether the optimal linewidth and roughness is achieved; and 
 (d) instructions for post baking the substrate if the roughness is not acceptable. 
 
   
   
     17. The storage medium defined in  claim 16 , wherein the linewidth figure of merit is equal to the average, minimum and maximum of a line region. 
   
   
     18. The storage medium defined in  claim 16 , wherein the roughness figure of merit is equal to the maximum linewidth minus the minimum linewidth of a line region.